[Medical Q&A] Do you know the importance of eyelashes to vision protection?

Author: Luo Ban, deputy chief physician of Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology

Reviewer: Yang Hong, Chief Physician, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology

A normal person has more than 200 eyelashes, which are located at the upper and lower eyelid margins and grow outwards. They are like two rows of guards standing guard outside the eyes. When you blink, the upper and lower eyelashes move towards each other, blocking dust, insects and other uninvited guests from the eyes, forming the first line of defense for the eyes. In order to ensure the smooth protection of the eyes, eyelashes are renewed every 3 to 5 months. On average, several eyelashes fall off every day, and they will grow naturally again after a few days. When the number or quality of eyelashes is abnormal, it may affect the defense function of eyelashes and cause some eye problems.

1. Fewer eyelashes If eyelashes fall off too much or have problems growing, they will become sparse or even absent, also known as "bald eyelashes". At this time, the eyes lose their first line of defense, and foreign invaders (dust, foreign objects, etc.) can easily enter and cause eye damage. How to prevent it? First, pay attention to eye habits, avoid excessive eye use (such as looking at mobile phones or computers for a long time), wear glasses correctly, etc.; secondly, pay attention to eye hygiene, wash hands frequently, keep towels clean, and avoid or reduce the use of cosmetics such as mascara.

2. There is a problem with the quality of eyelashes. Normal eyelashes are located at the upper and lower eyelid margins and grow outward from the eyeball without touching the eyeball. If the eyelashes grow inward and touch the eyeball, especially the cornea, it will not only fail to protect the eyes, but due to the movement of the eyeball, the eyelashes will rub the surface of the cornea like a brush, scratch the cornea, cause corneal epithelial detachment, and lead to foreign body sensation, photophobia, tearing, eye pain and other discomfort symptoms. This is what doctors call "trichiasis", which refers to an abnormal position of eyelashes that tilts toward the eyeball and stimulates the cornea and conjunctiva. At this time, it is recommended to seek medical treatment for trichiasis correction as soon as possible.